Nitroso derivatives



" 050 DERIVATIVES No Drawing. Application September 16, 1955, Serial No. 534,834

Cl priority, application France September 17, 1954 20 Claims. (Cl. 8-12) The present invention concerns improvements in and relating to nitroso derivatives.

It has been known for a very long time that the orthonitroso derivatives of phenols and naphthols give, with ferrous salts, complex salts of green shades which are very fast to light. In particular, the ferrous complex of 1-nitroso-2-naphthol, which forms a green pigment which is practically insoluble in an aqueous acid or alkaline medium, is known. On the other hand, the same compound sulphonated in the 6-position is soluble and has been employed for dyeing ,wool in a bath acidified with sulphuric acid. Moreover, for some years the technique of wool dyeing has been directed towards the use of dyestuffs capable of dyeing in a neutral bath or in a bath made slightly acid by means of an organic acid; this method of dyeing, in fact, shows, amongst other advantages, that of better care of the fibre. The dyes suitable for this technique are most generally the metallic complex compounds of o:o'-dihydroxy-azo or o-carboxy-o'- hydroxy-azo dyestufis which contain no sulphonic group or carboxyiic group other than that which eventually takes part in the complex. Neither the insoluble ferrous complex of l-nitroso-Z-naphthol nor its sulphonated derivatives are suitable for this method of dyeing. The replacement of the sulphonic group by a sulphonamido group alone seems to have brought an acceptable solution. It has been mentioned in German Patent No. 869,103 that the ferrous complex of l-nitroso-6sulphon amid0-2-naphthol is suitable for dyeing wool in a neutral or weakly acid bath.

It has now been found that the nitroso derivatives corresponding to the general formula in which X in one position represents a CH or C-halogen group, and in the other position a nitrogen atom, and Y and 2 represent a hydrogen or a halogen atom, give with ferrous salts complexesof green shades, which are sufficiently soluble in an aqueous medium or in a medium made weakly acid by means of an organic acid to allow the dyeing of wool, silk, leather, superpolyamides or superpolyurethanes, without the use of any dispersing or solubilising agent. Under these conditions of dyeing, these compounds show excellent affinity and provide shades of pure green or verging on olive which have very good general fastness.

The nitroso derivatives of the hydroxy-indazoles mentioned in the preceding paragraph are new and as such form part of the invention. They can be obtained by the action of nitrous acid on the corresponding hydroxyindazoles. The ferrous complexes of these nitroso- 2,787,515 Patented Apr. 2, 1957 hydroxy-indazoles are also new and form part of the invention. They are obtained by the action of ferrous salts on the corresponding nitrosohydroxy-indazoles. By reaction with amines such as the substituted derivatives of guanidine, cyclohexylamine, or the butylamines, they are capable of giving salts which are insoluble in water but soluble in organic solvents such as the alcohols, polyhydric alcohols, esters or ketones.

When the derivatives of S-hydroxy-indazole and 6-hydroxy-indazole are mentioned in the text, products are referred to whose formulae are usually represented in the following way:

For convenience of explanation, the indazole derivatives are represented by a formula derived from the following:

and

This representation is one of those possible for indazole derivatives, more generally represented by formulae derived from the following:

The invention will be more clearly understood by reference to the following examples which are purely illustrative and in which the parts indicated are by weight except when the contrary is indicated.

EXAMPLE 1 13.4 parts of 6-hydroxy-iudazole are dissolved in 100 parts byvolume of normal soda solution. 7 parts of sodium nitrite dissolved in 10 parts of water are added. The well stirred mixture is cooled to 0-2" C. and 240 parts by volume of normal sulphuric acid are introduced under the liquid in the space of 2 hours. An orange mass is formed which is made up of the nitroso derivative. At the end of the introduction of-acid, the acidity is tested on Congo red paper and the presence of a slight excess of nitrite verified. The mass is stirred for 16 hours, while gradually allowing the temperature to rise again to the atmospheric temperature. 14 parts by volume of 10 N caustic soda are then introduced in order to obtain complete solution, and then over half an hour a solution of 14 parts of hydrated ferrous sulphate in 100 parts of water. The green ferrous complex precipitates and the aureole of a drop on paper must not be yellow. It is filtered, allowed to drain thoroughly and dried at 9095 C. The weight collected is 19.5 parts. This complex has a solubility of 12 to 14 g, per litre at 90 C. and dyes wool and nylon in a bath weakly acid with acetic acid and a pure and bright green shade, having very good fastness.

3 The nitroso derivatives of .6:hydroxy-indazole, .not described in the literature, has been submitted to analysis,

Calculated for LFound .C7H5OzN3 0, Percent 51. 5 61.4 H, Percent 3.06 3.50 N, Percent 25. 7 25. 5

EXAMPLE 2 13.4 parts of 6-hydroxy-indazole are dissolved in 250 parts by volume of normal hydrochloric acid. Ice is added to reduce the temperature to 5 C. and a solution of 7 parts of sodium nitrite in 50 parts of water is introduced below the well stirred liquid in the space of minutes. The derivative begins to precipitate from the beginning of the operation. After 2 hours of stirring at between 5 and 10 C., parts by volume of 10 N caustic soda are added and this addition brings about complete solution of the nitroso derivative. The nitroso derivative obtained probably consists of 7-nitroso-6-hydroxy-indazole. The preparation of the ferrous complex is finished as in Example 1.

EXAMPLE 3 The 6-hydroxy-indazole in Examples 1 or 2 is replaced by 5-hydroxy-indazole and a. green ferrous complex is obtained, under exactly the same conditions, which dyes wool and nylon in a green shade verging on olive, which has very good fastness.

Analysis of the nitroso derivative Calculated for C7H5O2N3, H2O

Found 0, Percent 8. 8 H, Percent 3.4 N, Percent 4. 4

This nitroso derivative is probably 4-nitroso-5-hydroxyindazole.

EXAMPLE 4 3-chloro-6-nitro-indazole can be advantageously prepared by the action of a slight excess of calcium hypo- Analysis Calculated for C1H5ON2CI Found 0, Percent 01, Percent..

This same derivative can also be obtained in the following manner: 16.7 parts of 3-chloro-6-amino-indazole are dissolved with heating in 250 parts by volume of 20% sulphuric acid. The product is cooled to 3-5 C. and 14 parts by volume of a 50% solution of sodium nitrite are poured in at one time. The mixture is agitated for 10 minutes, filtered and the filtrate introduced over a period of an hour and a half into a mixture composed of 60 parts by volume of 66 B. sulphuric acid and 55 parts of water, and heated at 150 C. After the addition is completed the product is allowed to cool for 10 minutes and 500 parts of ice water are added. A small amount of insoluble matter is filtered off and the 3-chloro-6-hydroxy-indazole is extracted from the filtrate with ether. After evaporation of the solvent, 11.5 parts of the indazole derivative are obtained.

The 6-hydroxy-indazole in Example 1 is replaced by 16.8 ,parts of 3-chloro-6-hydroxy-indazole, andthe introduction of the nitroso group and the metallisation operation are finished according to the same method. The nitroso derivative obtained, which is probably 3- chlor0-7-nitroso-6-hydroxy-indazole, provides a green ferrous complex, in great part dissolved. The precipitation is completed by salting out at about 15%, and at 7580 C., the product is filtered, drained and dried at 100 C.

The complex thus prepared is much more soluble than those described in Examples 1, 2 and 3. It dyes wool and nylon in a green shade of great brilliance and slightly more bluish than that provided by the complex of Examples l and 2. The general fastness is excellent.

EXAMPLE 5 On reducing 3-bromo-6-nitro-indazole by the action of iron. powder in a medium of dilute hydrochloric acid, 3- bromo-6-amino-indazole of melting point 220 C. is obtained. This product, when subjected to hydrolysis by sulphuric acid under the same conditions as the 3-chloro derivative cited in Example 4, gives 3-bromo-6-hydroxyindazole with melting point 215 C.

'On replacing the 3-chloro-6-hydroxy-indazole in Example 4 by 21.3 parts of 3-bromo-6-hydroxy-indazole, there is obtained, under the same conditions, a green ferrous complex a little less soluble in water, but with very similar dyeing properties. This ferrous complex is probably that of 3-bromo-7-nitroso-6-hydroxy-indazole.

EXAMPLE 6 40.3 parts of 5-chloro-4-nitro-2-amino-toluene are dissolved in 1500 parts by volume of glacial acetic acid, the solution is strongly agitated and 30 parts by volume of a 50% solution of sodium nitrite poured in all at once at 15 C. The mixture is allowed to stand for 20 hours, then distilled under vacuum until extensive crystallisation occurs, diluted with 500 parts of water and filtered. There are thus obtained, after drying, 37 parts of 5- chloro-6-nitro-indazole of melting point 188 C., when recrystallised from alcohol it appears in the form of fine, light yellow, needles of melting point 194 C. By reduction of this derivative by means for example of iron and dilute acetic acid, 5.-chloro-6-amino-indazole of melting point 219 C. is obtained. On treating the 5-chloro- 6-amino-indazole With ten times-its Weight of 10% sulphuric acid in an autoclave for 6 hours at 190-200 C., 5-chloro-6-hydroxy-indazole of melting point 229-230 C. is obtained.

The 6-hydroxy-indazole in Example 1 is replaced by 16.8 parts of 5-chloro-6-hydroxy-indazole, and the introduction of the nitroso group and the metallisation operation are finished according to the same method. The nitroso derivative obtained is probably 5-chloro-7- nitroso-6-hydroxy-indazole. The ferrous complex is precipitated, and is filtered, drained and dried at 100 C.

This product.dyes'-wool:andnylon ina neutral bath or in a bath slightly acid with acetic acid in a bright and full-bodied green shade, more yellowish than that provided by the complex of Examples 1 and 2, and possessing excellent general fastness.

EXAMPLE 7 11 parts of the ferrous complex of 3-chloro-7-nitroso- G-hydroxy-indazole, obtained according to the method of preparation described in Example 4, are dissolved in 200 parts by volume of ethyl alcohol at 95 and 50 parts of water. The solution is filtered in order to separate possible traces of insoluble material. The solution is agitated and a solution of 12 parts of di-ortho-tolylguanidine in 100 parts of water and 50 parts by volume of normal hydrochloric acid is introduced therein at 30 C. The formation of a green precipitate is immediately observed. It is taken to 60 C. for some minutes, left to cool, filtered and thoroughly washed. The di-orthotolylguanidine salt thus obtained is dried at 100 C. This dye, insoluble in water, is soluble in organic solvents such as alcohols, polyhydric alcohols, and esters and is particularly suitable for the coloration of varnishes and compositions for printing inks.

EXAMPLE 8 The solution of di-ortho-tolylguanidine of Example 7 is replaced by that obtained by dissolving 5 parts of cyclohexylamine in 100 parts of water and 50 parts by volume of normal hydrochloric acid and on operating in a similar manner a green dye endowed with very similar properties is obtained.

We claim: 1. Nitroso derivatives of the following general formula:

in which X in one position represents a member selected from the group consisting of the CH and C-halogen groups, and in the other position a nitrogen atom, and Y and Z each represent a member selected from the group consisting of the hydrogen and halogen atoms.

. 7-nitroso-G-hydroxy-indazole. 4-nitroso-S-hydroxy-indazole.

. 3chloro-7-nitroso-6-hydroxy-indazole.

. 3-bromo-7-nitroso-6-hydroxy-indazole.

. chloro-7-nitroso-G-hydroxy-indazole.

Process for the preparation of a nitroso derivative which comprises reacting nitrous acid with a hydroxyindazole of the following general formula:

X Y \NH on X/ in which X in one position represents a member selected from the group consisting of the CH and C-halogen groups, and in the other position a nitrogen atom, and Y and Z each represent a member selected from the group consisting of the hydrogen and halogen atoms.

8. A process as claimed in claim 7 in which the hydroxy-indazole used is 6-hydroxy-indazole.

9. A process as claimed in claim 7 in which the hydroxy-indazole used is 5-hydroxy-indazole.

10. A process as claimed in claim 7 in which the hydroxy-indazole used in 3chloro6-hydroxy-indazole.

11. A process as claimed in claim 7 in which the hydroxy-in-dazole used in 3-bromo-6-hydroxy-indazole.

12. A process as claimed in claim 7 in which the hydroxy-indazole used is 5-chloro6-hydroxy-indazole.

13. Process as claimed in claim 7 in which the nitroso derivative is converted into its ferrous complex by reaction with a ferrous salt.

14. Process for the coloration of material selected from the group consisting of wool, silk, leather, superpolyamides and superpolyurethanes in a bath, which is at most slightly acid in which the colouring agent is a ferrous complex of a nitroso derivative of the following general formula:

in which X in one position represents a member selected from the group consisting of the --CH and C-halogen groups, and in the other position a nitrogen atom, and Y and Z each represent a member selected from the group consisting of the hydrogen and halogen atoms.

15. Ferrous complexes of nitroso derivatives of the folowing general formula:

\NH on- X/ in which X in one position represents a member selected from the group consisting of the --CH and C-halogen groups, and in the other position a nitrogen atom, and Y and Z each represent a member selected from the group consisting of the hydrogen and halogen atoms.

16. The ferrous complex of 7-nitroso-6-hydroxyindazole.

17. The ferrous complex of 4-nitroso-5-hydroxyindazole.

18. The ferrous complex of 3-chloro-7-nitroso-6-hydroxy-indazole.

19. The ferrous complex of 3-bromo-7-nitroso-6-hydroxy-indazole.

20. The ferrous complex of 5-chloro-7-nitroso-6-hydroxy-indazole.

No references cited. 

1. NITROSO DERIVATIVES OF THE FOLLOWING GENERAL FORMULA:
 14. PROCESS FOR THE COLORATION OF MATERIAL SELECTED FROM THE GROUP CONSISTING OF WOOL, SILK, LEATHER, SUPERPOLYAMIDES AND SUPERPOLYURETHANES IN A BATH, WHICH IS AT MOST SLIGHTLY ACID IN WHICH THE COLOURING AGENT IS A FERROUS COMPLEX OF A NITROSO DERIVATIVE OF THE FOLLOWING GENERAL FORMULA:
 15. FERROUS COMPLEX OF NITROSO DERIVATIVES OF THE FOLLOWING GENERAL FORMULA: 